Cyclic imido esters have been prepared by reacting nitriles with amino alcohols and driving off the resultant ammonia, at temperatures of between 50.degree. and 180.degree. C., as disclosed in, e.g., DOS No. 2,127,776, corresponding to U.S. Pat. No. 3,813,378, the disclosure of which is incorporated herein by reference. Suitable catalysts employed include metallic salts which are sufficiently dispersible in the reaction medium. In general, the reaction is carried out at atmospheric pressure. According to the aforementioned reference, it is possible to conduct the reaction under elevated or reduced pressure. However, the reference further teaches that operating under reduced pressure may be advantageous because the ammonia produced is thereby immediately removed from the reaction medium. However, one disadvantage in this process is the very long reaction time.
Therefore, a need still exists for an improved process which avoids the disadvantages of known processes.